rieffel and n



RIE FFEL & THORN.

Dividers. v No. 5,929. Patented Nov. 21, 1848.

N. PETERS. Piwlo Lhhngr-mpher. Walhinglolv. D. C.

CHAS. RIEFFEL AND N. THORN, OF NEW YORK, N. Y.

DIVIDERS OR MEASURING-COMPASSES.

Specification of Letters Patent No.. 5,929, dated November 21, 1848.

To all whom iv may concern:

Be it known that we, CHARLES RIEFFE'L and NIOKOLAUS THORN, both of thecity, county, and State of New York, have invented a new and usefulImprovement in Compasses or Divide-rs; and we do hereby declare that thefollowing is a full and exact .description of the construction andoperationof said im'-- provement, reference being'had to the annexeddrawing, making part of this specification, in which- Figure 1 is afront View, and Fig. 2 is a transverse section, representing sections of.the adjusting screw and of the conical pivotplugs through which theadjusting screw passes.

The improved compasses or dividers are, in many respects, constructed inthe ordinary form, with legs A A, connected by a head pivot joint 13. Atthe distance of an inch or more below the pivot joint, each leg has aswell C C through which is an orifice one fourth or three eighths of aninch in diameter, and parallel to the pivot of the head joint; and ineach orifice is inserted a conical pivot plug D E, which plug, however,consists of two equal half-parts D and E, each of which is nearlysemi-cylindrical, but a trifle larger at one end than at the other.

through each half of each pivot plug, 'in a direction at right angleswith the crevice between the two half parts of each plug. This adjustingscrew, is furnished with a milled head G, and at its longitudinal centerH,

midway between the head and the opposite end, its thread is reversed,being a leftt-hread from the head G to the center H,

and a right thread thence to the end F. The

swells C C are each perforated in the direction of the screw, with aslot or oblong orifice, (partly shown I I Fig. 2,) through which theadjusting screw passes, and by which its various relative positions areaccommodated as the legs A A are made to approach, or recede from eachother. The

two half parts of each pivot plug are so adjusted upon the adjustingscrew, that a minute space exists between. them; and a small steel platespring K K is so adjusted as to pass over and press upon the head orlarge end of each pivot plug; each end of each spring being attached tothe leg by a small screw; and by the pressure of the springs upon thepivot-plugs the two half parts of each are made to approach each otherso as to gently press upon the threads of the adjusting screw, thusinsuring a motion of the legs in obedience to the slightest motion,rotarily, of the adjusting screw.

'lVhat we claim as our invention and desire to secure by Letters Patent,is

The two pivot-plugs D E constructed and adjusted as herein described. Astraight adjusting screw F G passes CHARLES RIEFFEL.

NICKOLAUS THORN.

Witnesses:

JOHN LEWIS, WM. H. STARR,

